1. The Field of the Invention
The present invention relates to compositions and methods for increasing fertility in a mammal using cationic steroidal antimicrobial (CSA) compounds.
2. The Relevant Technology
Maintaining fertility in dairy cows, horses, domestic animals, and other mammals continues to be of importance to those engaged in the farming industry. Loss of fertility greatly reduces the value of breeding animals, which can only then be used for meat but which may not be suitable for such use. Thus, fertility loss, especially premature infertility, may substantially or completely destroy the economic value of an animal relied upon for breeding.
In general, there may be many reasons to restore or enhance fertility in a wide variety of different mammals, including humans. Current treatments to enhance fertility include administration of fertility drugs, including hormones or other substances that act by accelerating ovulation, and/or surgical procedures, some of which can be very invasive and expensive.
In addition to old age, infertility may also be caused by fungal or bacterial endometritis, which occurs when a bacteria or fungus (e.g., yeast) contaminates the uterus and causes infection and inflammation. In some cases, endometritis can be sexually transmitted, such as Contagious Equine Metritis (CEM), caused by Taylorella equigenitalis, a Gram negative coccobacillus. The bacteria can survive for an extended period on the external genitalia of the stallion and the vagina or clitoris of the mare. When infected, the stallion may show no clinical signs. The mare, however, typically presents acute endometritis with a thick, grey, mucoid discharge after breeding and may short cycle due to inflammation. The acute signs may subside rapidly, with some mares remaining as asymptomatic carriers.
Endometritis is difficult to treat and has a high rate of recurrence. Current treatments may include uterine lavage with large volumes of fluid and/or administration of dimethylsulfoxide (DMSO), antifungal agents (e.g., clotrimazole, amphotericin, fluconazole, nystatin), or antibiotics. Such treatments are expensive and outcomes uncertain. The prognosis is often poor since treatment only affects certain stages of bacterial or fungal development. In some cases, the microbe may be attached within folds of the endometrium, or the mare may have delayed uterine clearance. Even with successful treatment, chance of re-infection is high.
Accordingly, there remains a present but unsatisfied need to find reliable treatments for increasing fertility in mammals.